Idea - have an accuser send btc to
themselves in the future (using
lbaat.net).
* Ultimately get the coins back, only a 'hassle' to the accuser.
* Provable that the coins are locked up
* The farther coins are sent in the future and quantity can dictate how serious the allegations are.
Disclosure - I partnership with lbaat.net, but there is no money to be made from the site. Like most things bitcoin related I only pay!